Compare Peptides
Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.
Popular comparisons
IGF-1 LR3
Insulin-like Growth Factor-1 Long R3, Long R3 IGF-1
A splice variant of IGF-1 produced in response to mechanical stress on muscle tissue. Plays a key role in muscle repair by activating satellite cells. The non-PEGylated form has a very short half-life.
A synthetic analog of insulin-like growth factor-1 (IGF-1) with an extended half-life due to a modified arginine-3 sequence. IGF-1 is naturally produced in the liver in response to growth hormone. The LR3 variant is approximately 3x more potent than native IGF-1 and resists binding to IGF-binding proteins, extending its activity.
Activates muscle satellite (stem) cells, promoting their proliferation and differentiation into new muscle fibers. This is distinct from IGF-1's general anabolic effects — MGF specifically targets the repair response to mechanical damage.
Binds to IGF-1 receptors throughout the body, stimulating cell growth, proliferation, and differentiation. Promotes protein synthesis, glucose uptake, and fat oxidation. Activates the PI3K/Akt/mTOR pathway — the primary anabolic signaling cascade. Unlike GH secretagogues, IGF-1 LR3 acts directly at the tissue level rather than through the pituitary.
- Muscle repair after injury
- Hypertrophy support
- Recovery from intense training
- Localized tissue repair
- Muscle growth and hypertrophy
- Recovery from injury
- Fat loss
- Anti-aging protocols
- Athletic performance enhancement
- Very short half-life (minutes)
- Must be injected locally at target site
- Limited human data
- Potential for uneven growth if injection technique is poor
- Theoretical cancer risk (promotes cell proliferation)
- Hypoglycemia (blood sugar drop) — significant risk, especially post-workout
- Potential tumor growth promotion (IGF-1 pathway implicated in cancer)
- Acromegaly-like effects with chronic high-dose use
- Joint pain
- Water retention
- Limited long-term human safety data
- High abuse potential in athletic contexts
No FDA regulatory category. Available only as a research chemical. Not approved for any clinical indication.
Not FDA-approved and not on any compounding list. Available as a research chemical. One of the more potent anabolic peptides — the hypoglycemia risk is real and requires careful dosing. Not affected by the 2026 regulatory changes.
This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.